Lightly spray four 18” squares of aluminum foil with nonstick cooking spray. Place one fish fillet in center of each foil square and season each with one-fourth of salt and pepper; distribute one-fourth each of the zucchini, squash and leek evenly over each fillet. Top each with 1 Tbsp wine and 1 teas. juice. Make packets by bringing 2 sides of foil up to meet in center and pressing edges together in two 1/2” folds. Then fold edges of each end together in two 1/2” folds. Allowing room for packets to expand, crimp edges together to seal. Grill packets 10 minutes (packets will puff up). Remove packets from grill and open carefully, avoiding steam. Transfer contents to each of 4 plates and serve.